Strand tensioning device



Oct. 14, 1952 l. s. ROBERTS STRAND TENSIONING DEVICE Original Filed Dec. 16, 1947 INVENTOR. M/GHAM s. Roam 7.5

Patented Oct. 14, 1952 STRAND TENSIONING DEVICE Ingham S. Roberts, Ridley Park, Pa., assignor to American Viscose Corporation, Del., a corporation of Delaware Wilmington,

Original application December 16, 1947, Serial No.

791,963, now Patent No. 2,559,735, dated July 10, 1951. Divided and this application November- 25-, 1949, Serial No. 129,257

This invention relates to yarn or thread twisting machinery such as a tWo-for-one twister and particularly to devices for controlling yarn or thread tension during a twisting operation.

This application is a division of a prior application Serial No. 791,963, filed December 16, 1947, now Patent 2,559,735. The prior application discloses tension controlling devices and emergency the twister by a holder mounted on the twister spindle but held from rotating during the twisting operation. Yarn is drawn from the non-rotating supply package into one end of the rapidly rotating hollow twister spindle, then withdrawn at another point by a flyer and delivered to a rotating eccentric position. As the spindle is rotated, the yarn which progressively passes between the flyer and an overhead ring guide is acted upon by forces which cause it to follow a spiral path. This spiral path revolves about the axis to form an apparent balloon outline which is usually referred to as a balloon. From the overhead ring guide, the yarn passes to the package winding machine.

An important object is to provide a simple and inexpensive device for initially tensioning the yarn before or as it enters the hollow twister spindle. It is an object also to accomplish tensioning of yarn or thread during the twisting with a minimum of disturbance to the yarn structure or filament arrangement. Other objects, features and advantages will be apparent from the drawingsand the following description thereof.

. In the drawings illustrative of the invention,

Figure 1 is a side elevation partly in section of a two-for-one twisting machine embodying the invention;

, Figure 2 is a fragmentary view in section of a tension device supported by a conical package Figure 3 is a transverse sectional view of the members of a modified form of initial tens'ioning device;

Figure 4 illustrates a'variation of the device shown in Figure 3; and

5 Claims. (Cl. 242-449) Figure 5 is a. top view of an initial tensioning device. I

Referring now to Figure 1; a two-for-one twists ing machine is shown comprising as its principal parts, a driving means such as an electric motor 12, a drive shaft l3, a hollow tubular shaft l4,-a package holder I5, and a fiyer I6. A ring guide 19 is supported rigidly above theimachine by means not shown. Since the various parts of the machine are supported either by the. driving means housing ll or the shaft [3, the machine may receive its principal support at the driving means housing I! by supporting means suchas the platform or rail lla. The-upper end of the,

drive shaft 13 terminates in a groove oblique-to its axis. The hollow spindle shaft M has an enlarged portion 22 which fits tightly over the upper end of shaft l3. The shaft I3 is drilled axially from the portion of the grooved surface-nearest the driving means to accommodate the two. ends of a U-shaped member 2| as shown in Figure 1; Spindle shaft [4 has an enlarged lower portion 22 which provides close-fitting and limited telescopic relation with the shaft 13 on the interior and forms an exterior shoulder 23 whereby the axial position of the fiyer I6 is determined. Shaft I4 is at least long enough to provide stable support of the package holder [5 at the'bearings 26 and 27. The enlarged portion 22 of shaft I4- is provided with an opening 22a aligned with the closed end of U-shaped member 2| so that yarn or thread may be introduced into the top end of shaft :4 and discharged beneath the flyer I'B.

The holder l5 comprises a base portion 30 act ing as a hub about the bearing 21, a lower cylindrical shell member 3| having a flange extending inwardly from its lower portion and secured thereby to the top surface, of base portion30, an upper hub member 35 for hearing 26, and a cylindrical sleeve 33 connecting the baseportion 3!] and the hub member 35. The shell member 3l.is provided with a chrome plated and polishedouter flange 32 about its top portion for minimizing frictional contact and abrasion of the strand'with the supply holder assembly during starting and stopping of the twisting machine. To prevent'the material being twisted from coming into contact] with a supply package 41 or with the yarn being drawn therefrom, a domed or conical cover such as the shell member 34 is supported'on amazontal surface 40 formed by an annular recess along tating about the smooth metal surface of the bottom of the shell member 3|, an annular fiat cushion 43 of felt or other soft protective material is placed within the member 3| at the package supporting surface. A Supply package of yarn, or other filamentary or textile material is ordinarily furnished on a rigid core of standard design such as the cylindrical member 36 of Figure 1. As both ends of the core generally extend beyond the yarn package, an annular recess 29 may be provided in the base portion 30 below the annular package-supporting surface of the member 3| to receive the lower end of the core 36. To the upper protruding end of core 36 is fitted a conical or domed cap 38 having an axial passageway 31. 'In order to control or restrict the path of yarn passing into the shaft l4 and to facilitate lacing-up the passageway of cap 38 may be extended by a cylindrical member 39.

An essential feature of the invention now to be'described is the tensioning device, comprising plates 4| and 42 mounted atop the cap 38, which prevents tangling of the yarn as it passes through the rotating spindle l4 and imparts to the yarn part of the total tension necessary to form 'a stable balloon-shape such as that indicated by numeral l8 in Figure 1. The shape of cap 38 is critically important; if it is too tall, the yarn will wrap around it and snub; if it is too short, the yarn tends to snub at the edges of the supply package. The slope of the side of the cap is then chosen so thatthe yarn spirals about the caphndslides smoothly and upwardly into the bite of tension plates 4| and .42. A cap having a slope of approximately 45 degrees has been found quite satisfactory although to meet specific conditions, slopes from 30 to 60. degrees with the horizontal are quite practical. Plate 42 has an annular upper yarn engaging surface and a central bore or passageway; it is firmly fastened to the cap 38 over the cap passageway 31. If desired, the plate 42 and the cap 38 may be formedlas a one piece structure. Plate 4| has a lower yarn engaging surface substantially meeting the yarn engaging surface of plate 42 and has a stem 44, preferably tapered, extending therefrom, of smaller diameter than the passageway of plate 42. A stem diameter approximately 0.80 that of the passageway diameter is quite satisfactory although stemdiameters in the range of 0.10 to 0.95 that of the passageway diameter may also be used. In-operation, yarn is drawn from. a supply package 41 and through the tensioning device horizontally between the plates 4| and 42. While the yarn is. betweenthe mating surfaces of the plates, its longitudinal speed is from five to ten times greater than its sidewise speed depending upon the diameter of the supply package. One result thereof is a helical yarn path between plates as shown in Figure 5 which revolves once about the plate 42 for each wrap removed from the supply package. Another result. is to slowly rotate the plate All in the direction indicated in Figure 5 and to ,move it laterally so that the stem 44r-rides-around the wall of the passageway of the plate 42 always at a point opposite the yarn path to provide a crescent-shaped clearance space at a preferred point for yarn traveltothe spindle shaft I14. I'his manner of operation prevents the yarn from being'p-inched. between the stem M and therplate 42 and from being subjected to tension variations due to spindle vibration.

. The weight of the plate 4| is chosen to produce may :be obtainedbymeans of inserts of a type 4 such as insert 48 shown in Figures 1 and 2, or small plate like discs 49 shown in Figure 3, or separate differently weighted plate units such as unit 4|b of Figure 4; a further feature embodied in the unit am of Figure 3 is the anti-friction element 52 which may rotate freely about a bolt 54 to reduce friction and wear on the stem and to produce a tensioning device less sensitive to spindle vibration. The bolt 54 holds the entire assembly together. Plate 4| and variations thereof and including attachments thereto as shown in Figures 3 and 4 are designed so that the top of the assembly does not offer obstruction to any loops of yarn which might occasionally jump over it when irregularities occur in operation.

The tension plate 4| and 42 may be of an abrasion resistant material such as a vitreous ceramic material including that known by the trade-name Alsimag, asintered powdered tungsten carbide including that known by the trade-name Carboloy, chrome-plated steel or tungsten alloy. The mating surfaces should be ground and should have rounded corners to provide a smooth path for the yarn to and from the tension control region. The mating surfaces should also be substantially horizontal and plane. Preferable proportions are approximately as shown; if the outside diameter of the plates is too large, the yarn wraps around the entrance groove formed at the peripheries of the mating surfaces; if the outside diamter is too small, mating surfaces are too narrow and unit pressure on the yarn becomes too great for preferred operation. Line contact between plates 4| and 42 should be used only to control very light tensions.

Figure 2 illustrates the invention with a twofor-one type of twister designed for supporting a yarn package having frusto-conical outer and inner surfaces. The upper diameter of a package insert 36a is Such that the initial tensioni-ng device plates 4| and '42 are supported directly on the insert 36m. -A tubular yarnguide 3911 is attached directly to plate 42. Similar members in Figures 1 and 2 are indicated. by the same reference numerals, parts having similar function in the two figures but modified structure are indi cated by the same reference numeral: except that the letter a is added tothe' numeral of Figure 2.

While preferred embodiments of the invention I have been shown, it i to be understood that changes and variations may be made without de+ parting from the spirit and scope of the invention as defined by the appended claims,

I claim:

1. A tension device mounted to receive a strand passing from a revolving path comprising a lower annular member having an upwardly-facing horizontal surface and a central vertical passageway terminating as an aperture' in the horizontal sur= face, and an upper element'having a downwardlyfacing fiat surface, a rounded upturned peripheral surface contiguous with the perimeter of the flat surface of the upper member, and a short stem of progressively decreasing diameter extending downwardly from a central portion of the flat surface of the upper member with the greatest diameter of the stem substantially les than: that of the passageway, said upper element being loosely supported on the lower element with the stem extending into the passageway.

2. A tension device mounted to receive a strand passing from a revolving path comprising a lower annular member having an upwardlyfacing horizontal surface and a central vertical passageway terminating asan aperture in the horizontal surface, and an upper element having a downwardly-facing flat surface, a rounded up.- turned peripheral surface contiguous with the perimeter of the flat surface of the upper memher, and a short tapered stem of progressively decreasing diameter extending downwardly from a central portion of the flat surface of the upper member with the greatest diameter of the stem substantially less than that of the passageway, said upper element being loosely supported on the lower element with the stem extending'into the passageway.

3. A tension device mounted to receive a strand passing from a revolving path comprising a lower member havin an upwardly-facing flat surface and a central vertical passageway terminating as an aperture in the flat surface, and an upper element having a downwardly-facing fiat surface, a rounded upturned peripheral surface contiguous with the perimeter of the flat surface of the upper member, and a short tapered stem extending downwardly from a central portion of the flat surface of the upper member, said upper element being loosely supported on the lower element with the stem extending into the passageway, and said tensioning device also comprising a plurality of disc-shaped weights varying in weight, means for securing the weights to the REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,445,721 Bartholomew July 20, 1948 2,492,581

Kingsbury Dec. 27, 1949 

